| 摘要 |
988,875. Tubular films; extrusion apparatus. JOHNSON & JOHNSON. Jan. 16, 1962 [Jan. 16, 1961], No. 1553/62. Headings B5A and B5B. A fluid mass of swollen collagen fibrils having a collagen solids content of above 2.5% is fed under pressure into a passageway between opposed surfaces, at least one of which is planar, the surfaces are rotated relative to each other to impart shearing forces to the collagen mass, and the mass is then extruded as a tubular body. The extruding mechanism comprises a disc mounted within an extruder housing and rotatable about the central axis of the extruder, a pair of surfaces above and below the disc and spaced from the upper and lower surfaces thereof to form a pair of smooth and continuous upper and lower passageways communicating around the perimeter of the disc, means for moving the fluid mass of collagen fibrils through the lower passageway and then in reverse radial direction through the upper passageway, means for rotating the disc to effect relative rotational movement between the surfaces of the disc and the planar surfaces above and below the disc and an annular discharge orifice communicating with the upper passageway. In one embodiment (Fig. 4) a cylindrical housing 102 contains a hollow mandrel 108 spaced from central opening 106 to form annular discharge orifice 111 through which a collagen film C is extruded into a coagulating bath. Disc 114, rotatable by ring gear 120, and forming a head on tubular drive shaft 116 forms with surfaces 150, 136 upper and lower passageways 148, 134. The collagen mass is fed via conduit 100 into bore 138 communicating with passageway 134. Under the action of the rotating disc, the collagen moves radially outwards along 134, round communicating passageway 144, then radially inwards along passageway 148, and thence to orifice 110. In other embodiments (not shown), the upper and lower surfaces, opposing the upper and lower surfaces of the disc respectively, may themselves rotate. These surfaces may form, in effect, a rotating shell containing a rotating disc. Also one or both of the walls comprising the annular orifice may be made to rotate. The transverse shearing forces imparted to the collagen fibrils orientate them in the plane of the wall of the extruded film. |
